A relation between an evaluation process and the appraisals is complex, especially in an agile environment (for example article and some other article). So, I will not go any deeper on that subject without knowing what is your "setup".
Surveys show what workers usually want:
- To earn adequately (to market value of their position)
- To have tools and autonomy needed to reach goals
- To progress (and know how to progress)
- To have clear and transparent rules
- To receive regular feedback
- To be under fair and just judgement
So, I believe any rule is fair as long as it is transparent, known upfront, reachable and fairly judged. One can have multiple levels of expertise with progression related to:
- Time / Experience
- Knowledge / Skills
- Achievements
- Relation to other workers (reviewing work, coaching)
- Engagement
LowerAchieving the lower levels of expertise may provide an appraisalsa compensation, also in form of support in trainings, certificates, while higher levels of expertise may require such certificates. Of course, such requirement doesn't mean it's the only criteria of an appraisal...